CentOS 7 and Hyper-V

I'm trying to install CentOS 7 using Hyper-V and it's failing with the following error message:

tsc: Fast TSC calibration failed
PCI: Fatal: No config space access function found
i8042: No controller found

[long waiting period...]

dracut-initqueue[475]: Warning: Could not boot.
dracut-initqueue[475]: Warning: /dev/disk/by-label/CentOS-7-livecd-x86_64 does not exist
dracut-initqueue[475]: Warning /dev/mapper/live-rw does not exist
Warning: /dev/disk/by-label/CentOS-7-livecd-x86_64 does not exist
Warning: /dev/mapper/live-rw does not exist

Generating "/run/initramfs/rdsosreport.txt"

I have created a Generation 2 virtual machine and disabled Secure Boot so it would at least start booting.

CentOS 7 currently does not support running on Hyper-V Generation 2 virtual machines, as can be seen here. You have to recreate the VM and specify Generation 1 as the VM type.

Linux Virtual Machines on Hyper-V provides a comprehensive list of which distributions are supported and any limitations associated with them.

For a list of the differences between Gen1 and Gen2 virtual machine, check this page. You'll notice Legacy BIOS is gone in favor of UEFI.

You don't need to switch back to a Generation 1 virtual machine. You can use a Generation 2 virtual machine, so long as you disable Secure Boot.

To quote from Microsoft:

Generation 2 virtual machines have secure boot enabled by default and Generation 2 Linux virtual machines will not boot unless the secure boot option is disabled. You can disable secure boot in the Firmware section of the settings for the virtual machine in Hyper-V Manager or you can disable it using Powershell:

Set-VMFirmware –VMName "VMname" -EnableSecureBoot Off

Supporting Secure Boot is still a work-in-progress in most Linux distributions.